1. Field of the Invention
The present invention relates to a video projection apparatus for projecting a video to a wall surface, a screen surface, or the like, and more particularly to a video projection apparatus which employs a structure in which a projection direction of the video can be easily changed to an arbitrary direction, a size of the entire apparatus is small, and portability is superior.
2. Related Background Art
Up to now, in a video projection apparatus such as a liquid crystal projector, a video based on a video signal inputted from the outside or a video stored in an internal memory (video storing means) is enlargedly projected onto a screen surface. A video projection apparatus which employs a structure in which a video displayed on a small video display means such as a liquid crystal panel is illuminated with a light flux from a light source means for emitting intense light to enlargedly project the video to a large imaging area such as a screen has been known as such a video projection apparatus (Japanese Patent Application Laid-open No. H10-260473 or Japanese Patent Application Laid-open No. H06-082765).
A scanning projection display apparatus for projecting a light beam onto a predetermined surface using a scanning optical system to display a video has been also known (Japanese Patent Application Laid-open No. 2003-029182).
According to the video projection apparatus disclosed in Japanese Patent Application Laid-open No. H10-260473, a video is displayed on the liquid crystal display panel based on a video signal inputted from the outside. A light flux from the liquid crystal display panel illuminated with a light flux from the light source means is projected to a screen provided in a predetermined direction by a projection lens through a mirror provided in a pivotable cover member.
According to Japanese Patent Application Laid-open No. H06-082765, disclosed is a liquid crystal projector whose projection main body can be set at various angles by using a leg part relative to an adapter to project a video in an arbitrary direction.
According to the scanning projection display apparatus disclosed in Japanese Patent Application Laid-open No. 2003-029182, a resonance type mirror and a galvanomirror are used for a scanning means. A scanning member in a horizontal direction is driven with a sine wave for two-dimensional scanning to project a video.
In general, the video projection apparatus is large in size and heavy, so that the projection direction of the video is substantially determined. According to Japanese Patent Application Laid-open No. H06-082765, for example, a base for changing the projection direction is fit onto a main body, thereby changing the video projection direction. Although the projection direction can be changed in such a manner, the amount of change is small. Therefore, for example, it is hard to change the projection direction from the ceiling of a room to the wall surface thereof. A size of the apparatus itself is likely to increase because the base is fit.
According to Japanese Patent Application Laid-open No. H10-260473, a mirror is located in an exit port of the video as a means for changing the projection direction of the video without the movement of the video projection apparatus itself, thereby changing the projection direction. When the projection direction is intended to significantly change using a method of locating the mirror, a size of the mirror becomes very large, with the result that a size of the apparatus increases. When the method of locating the mirror is used, a changeable projection direction is limited to only a single direction.